First four Brent platforms
Images of the first four Brent platforms (Alpha, Bravo, Charlie, Delta) Source: Subsea World News
Expertise
Offshore Pipelines
r+k has longstanding experience with offshore pipelines, based on the experience with onland pipelines, but extended with the typical sea environment conditions.
Experience with offshore pipelines started in 1972 with a request of Shell UK Expro to assist, based on its onland pipeline analysis developments, with the design and analysis of riser-tie in structures. The start was the interaction between the riser, (attached to the platform structure) and the sea line, (often on a slippery sea floor) with the tie-in in between. Each element has its own conditions and its own contractor and thus its own approach to analysis. That’s why the boundary conditions at the interfaces between these three elements became the problem. The pipeline structure, however, acts as one structure and r+k Consulting Engineers was asked to integrate the behaviour of the pipeline as a whole.
One aspect that evolved from these studies was the development of the dog-leg type tie-in.
ther experiences followed, i.e.:
- on-bottom stability
- differentiated riser tie-in structures
- bottom tow and J-tube riser pull-in
- free span analyses
- pipeline self burying
- upheaval buckling (overbending onland)
- presweeping
- incident analysis (e.g. anchor hooking, cable sawing…)
Wave and current loadings are a typical offshore aspect.
Development and applications in analyses are based on:
- long crested Airy waves
- short crested Airy waves (cross pattern)
- long crested 5th order Stokes waves
- 7th order current parabola (default)
- user-defined current profiles
Project
Offshore Brent Field
r+k Consulting Engineers designed many offshore pipeline structures for the Shell Brent field development, including irregularities like anchor accidents, riser misfits and design alterations. Our involvement started with these four platforms: Alpha, Bravo, Charlie, and Delta. r+k Consulting Engineers has done many projects on offshore pipelines, to start with the Brent oilfield development in the British sector of the North sea including the export pipeline to St. Fergus.
Brent Oil Fields
Other interesting offshore projects we've done
Analyses for floating drilling platforms
A number of analyses for floating drilling platforms (e.g. Staflo Torpedo, Seashell).
Pre-designs
Bottom and surface pipeline and hose tow, many SBM alterations, pre-designs for a rotating Pier at the fjord at Risavika, for a floating 2,000,000 T/Y LNG plant with 20,000 m3 storage capacity including a bow loading facility, for a deep water Pedestal Conductor, and many more.
Auk Field ELSBM
Design and detailing of the Auk Field ELSBM including its rescue due to a deviation from the design. The rescue was done by dewatering deep well pumps with a diameter of 80 mm.
Presweep design of the Solepitt pipeline.
The original design was made by the contractor that resulted in about 54 subsea dune tops to be dredged. The analysis was done with a rigid bottom profile. r+k analyses were done with soft bottom profile and taking into account the backtension that resulted in no more than 10 tops to be dredged. A saving of many millions pounds.
Flow line pull-in analyses
Various flow line pull-in analyses for underwater completion manifolds and J-tube risers.